For the purpose of use for decorative members and exterior components of electronic device materials, zirconia sintered body containing coloring agents, so-called colored zirconia sintered body has been desired. To date, zirconia sintered body that exhibit reddish color tones have been studied as such colored zirconia sintered body, and cerium oxide (CeO2) has attracted attention as a coloring agent.
For example, zirconia sintered bodies made of tetragonal zirconia that contain CeO2 in an amount of 0.5% by mole or more as a coloring agent and that are obtained by reducing cerium have been reported (PTL 1). These sintered bodies have color tones close to brown, such as orange, brown, and dark red.
A method for manufacturing an orange/red zirconia, the method including firing a zirconia powder that contains a stabilizer such as yttria or ceria in an amount of 3% to 20% by weight, a powder for forming a glass phase in an amount of 0.1% to 5% by weight, and copper oxide in an amount of 0.01% to 10% by weight, has also been reported (PTL 2). The sintered body according to PTL 2 mainly uses coloring due to copper nanoparticles.
Furthermore, a translucent zirconia sintered body has a cubic crystal structure that contains reduced ceria (Ce2O3) produced by reducing cerium oxide has been reported (PTL 3). The zirconia sintered body according to PTL 3 exhibits a stronger red color tone than zirconia sintered bodies that have been reported as exhibiting red colors.